[BUG] CLI hangs on macOS 15.7.4 ARM64 — shebang execution stuck in dyld_start

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Code CLI hangs indefinitely on all commands (e.g. claude --version) on macOS 15.7.4 ARM64. The process gets stuck in _dyld_start (macOS dynamic linker) and never completes. Both the standalone binary and npm-installed wrapper are affected. Requires Ctrl+C to exit.

Key finding: node "$(which claude)" --version works perfectly, but claude --version hangs. The issue is specific to shebang (#!/usr/bin/env node) execution.

What Should Happen?

claude --version should return the version string and exit, as it does when invoked via node "$(which claude)" --version.

Error Messages/Logs

No error is produced — the process simply hangs. Using macOS `sample` command on the hung process shows:

Call graph:
    8592 _dyld_start  (in dyld) + 0  [0x1029d1274]

The process never progresses past dynamic linking.

Steps to Reproduce

1. On macOS 15.7.4 (ARM64 / Apple Silicon), install via npm install -g @anthropic-ai/claude-code
2. Run claude --version
3. Process hangs indefinitely — no output, no error
4. Ctrl+C to exit
5. Verify the script itself is fine: node "$(which claude)" --version → returns 2.1.63 (Claude Code) immediately

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.63 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

• macOS 15.7.4, Apple Silicon (ARM64)
• Node v20.12.2 (installed via nvm)
• Shell: zsh (oh-my-zsh)
• Standalone binary from install.sh also hangs with identical dyld_start stack
• Codesign validation passes, no quarantine attributes
• /usr/bin/env node --version works fine independently
• Workaround: alias claude="node $(which claude)" in ~/.zshrc

Possibly related: #27045 (Homebrew cask hangs on startup on macOS arm64)